A total synthesis of dl-pentalenolactone is proposed. Broad spectrum antibiotic properties have been ascribed to his compound. A key element is the use of consecutive Diels-Alder reactions to establish the carbon skeleton. In the second step a structurally symmetrical dienophile is used to insure unidirectionality and an extraneous carboxyl is to be removed in the form of a vinylogous Beta-ketoacid. Intramolecular aldolization and conjugate addition are envisaged to complete the carbon framework. The alpha-epoxy-sigma-lactone is to be introduced via the alpha-methylene-sigma-lactone. Ready access to analog structures is expected. A new approach toward the facile construction of prephenic acid is envisaged. The strategy involves new Diels-Alder dienes for the rapid construction of the required 4,4-disubstituted cyclohexadienone intermediates. By appropriate choice of dienophiles the parent compound as well as potential inhibitors of aromatic amino acid synthesis may be readily available.